<template>
    <div class="sidebar">
        <el-menu class="sidebar-el-menu" :default-active="onRoutes" :collapse="collapse"
                 text-color="#303133" active-text-color="#409eff" unique-opened router>
            <template v-for="item in items">
                <template v-if="item.subs">
                    <el-submenu :index="item.index" :key="item.index">
                        <template slot="title">
                            <i :class="item.icon"></i><span slot="title">{{ item.title }}</span>
                        </template>
                        <template v-for="subItem in item.subs">
                            <el-submenu v-if="subItem.subs" :index="subItem.index" :key="subItem.index">
                                <template slot="title">{{ subItem.title }}</template>
                                <el-menu-item v-for="(threeItem,i) in subItem.subs" :key="i" :index="threeItem.index">
                                    {{ threeItem.title }}
                                </el-menu-item>
                            </el-submenu>
                            <el-menu-item v-else :index="subItem.index" :key="subItem.index">
                                {{ subItem.title }}
                            </el-menu-item>
                        </template>
                    </el-submenu>
                </template>
                <template v-else>
                    <el-menu-item :index="item.index" :key="item.index">
                        <i :class="item.icon"></i><span slot="title">{{ item.title }}</span>
                    </el-menu-item>
                </template>
            </template>
        </el-menu>
    </div>
</template>

<script>
export default {
  data() {
    return {
      collapse: false,
      items: [
        {
          index: "sectionOne",
          title: "sectionOne"
        },
        {
          index: "1",
          title: "sectionTwo",
          subs: [
            {
              index: "sectionTwoFirst",
              title: "sectionTwo-1"
            },
            {
              index: "sectionTwoSecond",
              title: "sectionTwo-2"
            }
          ]
        },
        {
          index: "2",
          title: "sectionThree",
          subs: [
            {
              index: "sectionThreeFirst",
              title: "sectionThree-1"
            },
            {
              index: "sectionThreeSecond",
              title: "sectionThree-2"
            }
          ]
        }
      ]
    };
  },
  computed: {
    onRoutes() {
      return this.$route.path.replace("/", "");
    }
  },
  created() {}
};
</script>

<style scoped>
.sidebar {
  border-right: 1px solid #e6e6e6;
  display: block;
  position: absolute;
  background: white;
  left: 0;
  top: 70px;
  bottom: 0;
  overflow-y: scroll;
}

.sidebar::-webkit-scrollbar {
  width: 0;
}

.sidebar-el-menu:not(.el-menu--collapse) {
  width: 199px;
}

.sidebar > ul {
  height: 100%;
}
</style>
